Desensitization: A Numbed Pleasure Response

Printer-friendly version

Desensitization is just one of many brain changes caused by addiction. A few other major brain changes include;

  1. Sensitization: Formation of Pavlovian memory circuits related to the addiction
  2. Hypofrontality: Weakening of the impulse control circuits.
  3. Dysfunctional stress circuits - Stress will easily trigger a relapase

The neurotransmitter dopamine is the gas that powers our reward circuitry, and it is behind motivation, reward, desires, cravings, and of course, libido and erections. The level of dopamine signalling correlates to feelings of pleasure in human studies. Dopamine is the main player in reward and addiction, and the key to understanding desensitization.

A numbed pleasure response, or desensitization, is probably the best understood brain change that addiction induces. (There is another addiction-related brain change known as "sensitization." Here's an explanation that contrasts desensitization with sensitization). The main physiological feature of reward circuitry desensitization is a decline in dopamine signaling. Desensitization seems to be caused by a number of factors, including:

  1. Decline in dopamine (D2) receptors. Fewer D2 receptors mean less sensitivity to available dopamine, which leaves the addict less sensitive to the pleasure normally found in experiences.
  2. Decline in baseline (tonic) dopamine levels. Lower dopamine levels leave an addict "hungry" for dopamine-raising activities/substances of all kinds.
  3. Blunted dopamine in response to normal rewards. Dopamine normally rises in response to rewarding activities. Once your addiction is the most reliable source of dopamine, cravings arise urging you to use porn.
  4. Decline in CRF-1 receptors, which function to raise dopamine levels in the striatum (only studied with cocaine)
  5. Loss of reward circuit grey matter, which means a loss in dendrites. This translates into fewer nerve connections or synapses. A 2014 study on porn users correlated less grey matter with more porn use.
  6. Decline in opioids or opioid receptors

Both #2 and #3 may involve increased dynorphin which inhibits dopamine, and weakening of certain pathways (glutamate) conveying messages to the reward circuitry, In other words desensitization is rather complex, and an awful lot is left to learn.

What causes desensitization?

Too much of a good thing.

Dopamine is where it all starts. If dopamine is too high for too long it leads to nerve cells losing their sensitivity. If someone continues to scream, you cover your ears. When dopamine-sending nerve cells keep pumping out dopamine, the receiving nerve cells cover their "ears" by reducing dopamine (D2) receptors. (See: Volkow May Have Uncovered Answer to Addiction Riddle.)

  • The desensitization process can begin fairly quickly, even with natural rewards such as junk food. How quickly it occurs depends on the intensity of use and the vulnerability of the brain.
  • How much is too much is determined by brain changes - not by outward behaviors, such as the amount of drug used, calories consumed, or time spent watching porn. No two people are alike.
  • Abnormally high dopamine levels are not necessary to cause desensitization. Smoking hooks a far greater percentage of users than cocaine, even though cocaine furnishes a bigger neurochemical blast. Many small hits of dopamine can train the brain more thoroughly than fewer, more intense hits.
  • Nor do dopamine levels need to be continuously elevated to cause desensitization. Compare overeating and becoming obese to cigarette smoking. Both produce down regulation of dopamine receptors, but far less time is spent eating than puffing.
  • Overriding natural satiation mechanisms may be a key factor in how natural reinforcers trigger desensitization. Overeating and heavy porn users ignore 'stop' signals, or more accurately their addicted brains no longer experience "satisfaction," so they keep on consuming (see - Men: Does Frequent Ejaculation Cause A Hangover?)

Desensitization is behind tolerance, which is the need for greater and greater stimulation to experience the same "high." Porn users often escalate to new genres as way to jack up their lagging dopamine. Novelty and violated expectations (surprise) increase dopamine.

This is not a theoretical discussion of desensitization, as three recent Internet addiction brain studies assessed dopamine signalling in Internet addicts. Each measured different aspects of desensitization and found significant difference between Internet addicts and controls. In study #2, it specifically states - "watching online pornographies or adult movies".

  1. Reduced Striatal Dopamine D2 Receptors in People With Internet Addiction (2011)
  2. Reduced Striatal Dopamine Transporters in People with Internet Addiction Disorder (2012)
  3. PET imaging reveals brain functional changes in internet gaming disorder (2014)

In this study on porn users - Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014) - experts at Germany's Max Planck Institute found that higher hours per week & more years of porn viewing correlated with a reduction in grey matter in sections of the reward circuitry involved in motivation and decision-making. Reduced grey matter in this reward-related region means fewer nerve connections. Fewer nerve connections here translates into sluggish reward activity, or a numbed pleasure response. The researchers interpreted this as an indication of the effects of longer-term porn exposure.

  • Lead author Simone Kühn said - "That could mean that regular consumption of pornography more or less wears out your reward system."

Summary: When dopamine receptors drop after too much stimulation, the brain doesn't respond as much, and we feel less reward from pleasure. That drives us to search even harder for feelings of satisfaction—for example, by seeking out more extreme sexual stimuli, longer porn sessions, or more frequent porn viewing - thus further numbing the brain.

Desensitization versus habituation:

Habituation is a temporary decline or cessation of dopamine release in response to one specific stimulus. This is a normal process and can change moment to moment. Desensitization refers to long-term changes involving a decline in dopamine signaling and D2 receptors. This is an addiction process and may take months to years to develop, and a long time to reverse. 

Dopamine levels spike throughout the day in response to anything we find rewarding, novel, enjoyable, interesting, even frightening or stressful. The main message of dopamine is - "this is important, pay attention, and remember it."

Let's use eating as an example. When one is hungry, dopamine rises in anticipation of taking that first bite of a burger. As lunch continues, dopamine declines and we become habituated. No further spikes in dopamine signals means, "I've had enough." You may not want anymore burger, but if you are offered a chocolate brownie, your dopamine spikes, which urges you to override normal satiation mechanisms and have some.

Another example might have you flipping through pictures of your friend's trip to the Grand Canyon. You may receive a little spike of dopamine with each picture, but you quickly habituate and move to the next picture. Same thing might occur when clicking through pictures of Sport Illustrated swimsuit models. You linger on certain pictures (slow habituation), but not so with other pictures (fast habituation).

If I'm desensitized don't I need to avoid dopamine-elevating activities?

This is a logical question as all rewards share some overlapping brain structures. For example, if your brain is desensitized due to alcoholism or cocaine addiction, your chances of erectile dysfunction increase and libido generally decreases. That tells us overlap in brain circuitry exists. However, experience informs us that drinking wine, eating chocolate and having sex are different, which means each stimulus involves unique pathways in addition to the overlap.

Recent research found that sex activates it's own set of reward circuit nerve cells. Surprisingly cocaine & methamphetamine activates the exact same nerve cells in the reward center as do sexual rewards. In contrast, there's only a small percentage of nerve-cell activation overlap between meth and food or water (other natural rewards).

Additional research found that ejaculation in male rats can shrink the reward circuit nerve cells that produce dopamine. This normal event mimics the effects of heroin addiction on these same dopamine nerve cells. This doesn't mean sex is bad. It simply informs us that addictive drugs hijack the exact same mechanisms that urge us back into the bedroom for a romp.

Put simply, addictive drugs like meth & heroin are compelling because they hijack the precise nerve cells and mechanisms, which evolved to make sex compelling. Most other pleasures do not. Thus, the familiar "talking point" that "Everything raises dopamine. Golf or laughing are certainly not addictive, and how different can they be from internet porn in terms of dopamine increases?" falls apart.

You can't avoid dopamine-raising activities, nor should you. Normal everyday activities, and maybe even some alcohol and pot, shouldn't cause a problem. Sure, it would be great if you could stop all drugs, smoking, caffeine and eat really healthily, but men have recovered while still imbibing now and then.  

It's great to engage in natural rewards, such as kissing, cuddling, music, dancing, exercise, sports, good food, socializing, etc. Besides raising dopamine, most of these activities also rise oxytocin levels. Oxytocin is unique in that it both activates the reward circuit and decreases cravings. The bottom line is simple: Avoid what got you into this mess. I strongly suggest reading this FAQ: What stimuli must I avoid during my reboot?

What can I do to speed recovery?

A common question is: "What supplement or food will speed the return of dopamine receptors?" Your addiction was not caused by a nutritional deficiency, so it won't be corrected by a supplement. Dopamine receptors are proteins made from the same amino acids found in every one of your cells. Desensitization is caused by too much stimulation, not too few amino acids. If they wanted to, your nerve cells could rebuild the dopamine receptors in a few hours.

More importantly, desensitization involves multiple links in the reward chain undergoing alteration, which results in lower dopamine signalling (dopamine receptors & dopamine levels). You may have plenty gas (dopamine) in your tank, but your fuel pump is broken and half your spark plugs are missing. Adding more gas will do nothing to solve your problem.

Articles covering what to eat to raise dopamine levels are largely nonsense. First, L-tyrosine (often recommended) is the precursor for dopamine (and a few other important hormones). It is easily obtained in a normal diet. Second, "dopamine-containing foods" are of no value as dopamine doesn't cross the blood-brain barrier—meaning that what you put in your stomach won't help stabilize dopamine levels in your brain. Third, and most important, desensitization is primarily caused by a decline in dopamine (D2) receptors and changes in synpases. (For suggestions of those recovering see Supplements.)

What you can do is exercise and meditate. Aerobic exercise is the one thing that increases both dopamine and dopamine receptors. Exercise also reduces cravings and eases depression. One study reports that meditation increases dopamine a whopping 65%. Another study found far more frontal cortex gray matter in long-term meditators. Addictions cause a decrease in frontal cortex gray matter, which is associated with desensitization and less dopamine making it to the frontal lobes. Less gray matter is called hypofrontality, and correlates with poor impulse control.

[27 days without any PMO] "Here are the changes brought about in my own life from the "rebooting" process: The results are 100% real and palpable, and they permeate all aspects of my life. Without the PMO zombifying trance, I've been more comfortable in my own skin, and it seems it's been of great help in interactions with the opposite sex. I also get excited because so many other people have noticed the same effects: increased sexual attractiveness to women in more subtle situations, and increased desire to read and give responses to their cues. Also increased desire to socialize, and newfound confidence. This is no placebo effect, and for any skeptics; the only way to be convinced is to try it. You'll see."


hey gary, i got a question for you. Been a porn addict for 4-5 years and im in my early 20`s. Your information makes a lot of sence but however there is a problem. On dec 5, i decided to start a real reboot, I tried staying away from porn but i saw that young turks on porn induced ED documentary and there was porn in it so i had to reset . From then on i saw a pic of a girl by accident and yesterday an accident happened too and this is why i disable pics on my browser.

Problem is that the brain doesnt differentiate images coming from a tv, newspaper, magazine or pc right? my point is that its not just because im not on my laptop anymore that i can reboot right? In the society of today, there are arousal pics on tv, newspaper and etc and we cant avoid those (especially tv).

One aspect i think you forgot on the site is that when a porn addicent masturbates to porn for years, he finally realizes that he is in erection just after a few seconds. Why? because his brain is so used to porn that his penis becomes sensitive. this is an aspect forgotten to be explained on your site and thats what my doctor told me too.

THe problem is that i do notice me being in PONR state whenever i watch tv or hear music with a sexy voice or etc. My penis becomes sensitive like when I watch porn. Then how is it possible to reboot? Is there any medical intervention that can be done on a human being so he can rest while being alive for a few months? See where im getting Gary, now that would be a reboot right? I dont know anything besides coma.

Hope you reply .

porn ruins your brain

What stimuli must I avoid during my reboot (did I relapse)?

Nothing wrong with pics of cute girls. They don't cause "damage" anymore than being naked with a girl does. In fact, being with a real life naked girl would be beneficial - cause it's real.

It's your behavior that causes this addiction. Sitting in from of a computer, searching seeking, clicking from vid to vid, pic to pic. Avoid those things that trigger seeking porn on the Internet.

One aspect i think you forgot on the site is that when a porn addicent masturbates to porn for years, he finally realizes that he is in erection just after a few seconds. Why? because his brain is so used to porn that his penis becomes sensitive. this is an aspect forgotten to be explained on your site and that's what my doctor told me too.

I'm not real clear as two what you are saying here. Can you explain further? I do talk about what is called sensitization, which is getting a bigger buzz from porn - maybe that's what you mean? It's described here: Why Do I Find Porn More Exciting Than A Partner? - and here - Why do porn cues still trigger a rush (sensitization)?

Your sensitivity is sensitization, as described in the articles. Again, just avoid searching and watching porn and everything will heal.


hi my name is richard ive been watching porn since 12 start masturbating at 11... now i am a 15 year old male that is suffering from PMO.... i read this site and its was very benifitial to me but here are the qeustions.... 1 since im younger will i recover faster?... ive already been 4 weeks without PMO seen changes but had a great erection but i think im flatlining....2 is playing around will my girlfriend as in touching feeling kissing and foreplay will effect my progress at all? if so in what way......3 is it ok if i had sex with my girlfriend and avoided O (orgasm) or will it effect my progress aswell...... ive been a heavy porn user for 4 years what made me come around too stopping was when my gf got freaky for the first time and let me rub her and i couldent feel horny at all.... she wants me to take her virginity and this website helped alot.... but please answer and how long will it take thank you.

If you have ED, then avoiding orgasms will speed recovery. If you don't have ED then just stop porn and masturbation. This site is about real vs digital. Real is OK, digital is not. That's a simple way of approaching porn addiction.

I suggest this FAQ -

No one knows how long it will take. If it's ED - you should see improvements long after your erections come back.

Please you said to him he should stop porn and masturbation but he can have orgasms , do you mean he can have sex with someone but he can't masturbate ?


I can't thank you enough for this site !

Is it familiar or usual that one during the rebooting could have some extreme/ weird sexual desires & fantasies which don't necessary fit his normal urges ? .. I'm on day 30 of rebooting " No PMO , and these days I have some uncontrollable weird desires and images that I'm trying to drive them away from my head .. is it unfamiliar or just one of the possible symptoms that will be vanished later? ...

another question plz : I'm kinda confused about orgasms ! , as I know I can't have orgasm without masturbating ! , or at least touching and plying with my penis enough time to have an orgasm .. right ? .. I read a lot here about orgasm and masturbating as two separate things , it's stupid thing to ask but how can I know if I had an orgasm ? as far as I know I haven't had any during my last month of rebooting but I want to be sure that I'm not missing something about this... please answer and thx ... Modar

I can't thank you enough for this site !

Here's a short FAQ on them - How do I cope with porn flashbacks?

Most guys abstain from masturbation and orgasms when rebooting, but not all do. Other guys have orgasms through sex, but do not masturbate.

1_ How can I recognize my true libido from my addictive need to porn ? ( I'm now on 36th day of no PMO , had Ed )

2_ My exam is after a month from now , 'till then I'll be studying and I have so little chances to contact with women , Does this negatively affect the rewiring process and slow it down ? , Or the rewiring happens naturally with the abstinence from PMO ?


I can't thank you enough for this site !

1- You won't crave porn, but real women

2 - I really can't say

is it normal for my penis to feel cold during flatlineing? my penis temprature keeps jumping from normal to cold

but it may be the same mechanisms that causes shrinkage and numb feelings. I don't know the exact phsyiological mechanism for the flatline or cold feelings.

is it normal though? does this happen to others aswell? (the cold feeling)

- so it does happen.

Sorry if I give too much information, I just want to say anything that might be of use.

Hey,I'm 18 years old and I masterbaited on average once a day (sometimes a couple in one day sometimes I can go a couple days without doing it). I'm kinda desensitized, I'm not too sure how long this has been going on for (I want to say a year and a half).

I'm wondering if it's because of my lack of d2 receptors, or because this one time I masterbaited in the shower for the first time and I got shampoo in the hole in my penis and it hurt a little. Maybe that had something to do with it but I doubt it because a couple of weeks ago I had an orgasim that was pleasurable. and its not like I feel nothing all the time, most of the time i can feel something like 1/5 of what it's supposed to feel like.

I'm wondering how long it'll take me to heal because I'm going to be moving away for university in september and this girl from my high school that I like is going to go the same school. We've been talking & flirting and if we do decide to have sex I don't want my first time to be desensitized.

I haven't masterbaited in 4-5 days (its been hard). I wouldn't say that I'm addicted to porn, because I can get off and do it of imagination alone.

Hopefully you reply soon!

Only you can answer if your desensitization is due to porn use. And the only way to find out is to give up porn for several months. It really is that simple.

Good luck on your journey.


I have a little bit other "porn" addiction than the others here. Because I wach fitness modell girls on the internet.
I have been doing this for years, like someone waching porn. But the mechanism the same. picture to picture during long time... On facebook, instagram or youtobe... I have realised I don't like "normal" girls, they are not enough attractive for me or not so than these girls.

Unfortunately, I have a ED too, when I am waching these girls I have to help with my hand to maintain an erection.
I was totally depressed about it and I took a 2 months no fap period (I wached fitness girl but quite rarely), but my experience is that: I was almost every morning morning wood. I can have and maintain an erection without my hand but only for fitness girls. I wached a lot of normal hot girls, but nothing. No erection. Although I started to see the "normal" girls a little bit more attractive than before.

It was the time, when I have realised that I have a Fitness girls-induced Erectile Dysfunction. I know it is weird.

I would like to do a real reboot without waching and thinking about these fitness things. But if I go to the gym, there are several these kind of girls.
How will it effect to my reeboot and to my dopamine dysregulation? Is it ok because they are real girls and I see them only awhile? ( Not for hours and hours on the net)

"dopamine rises in anticipation of taking that first bite of a burger. As lunch continues, dopamine declines and we become habituated."
So if I look an attractive girl in real life even if that is a fitness one, it will be happen and that is why the dopamin in the normal way can't desenzitizate?

I am totally perplexed, what could I do. :(
Thank you for your reply!!

In fact, I remember two men who developed PIED with fitness models. This is really no different than PIED with hardcore porn: you have trained your brain to be aroused by a specific stimulus, and that stimulus doesn't match real sex with a real person.

If you haven't please watch  the adolescent video: Adolescent Brain Meets Highspeed Internet Porn (for all ages) and read First Sex: Just The Science Please

You have conditioned yourself to the hunt for specific images. The solution is same for every guy with PIED:

1) Stop all artificial sexual stimuli (don't just "cut back for a couple of months")

2) Rewire your sexual arousal to real people: Start dating, start looking at girls, being around girls.

Must do both.


I have an important question to ask, and I cant seem to find a good answer anywhere. I have ADHD and am in the early stages of rebooting. Will taking my ADHD medication, amphetamine and dextroamphetamine combo, slow down my reboot process? I know this drug causes dopamine release, as does porn, so will it take longer for my brain to get re-sensitized since I am getting this synthetic dopamine release still? Or will it not have any effect on my reboot time? Thanks.

Pavlovian conditioned responses to porn and to cues related to porn. Rebooting may also bring about greater sensitivity and frontal cortex functioning. It also involves countless psychological changes. so many aspects of rebooting other than reversal of low dopamine. Just give up porn and replace it with other activities.

Keep in mind that many alcoholics recover while smoking, eating junk food, and drinking coffee, (and taking meds).